1. Field of the Invention
The present invention relates to a solar cell and a manufacturing method thereof.
2. Description of the Related Art
A conventional solar cell generates electrical energy from solar energy. The solar cell is environmentally friendly, and its energy source is virtually endless. In addition, the solar cell has a long lifespan. Examples of the solar cell include a silicon solar cell and a dye-sensitized solar cell.
The silicon solar cell includes a semiconductor substrate and an emitter layer that constitute a p-n contact area having different conductive types, an insulation layer and a front electrode that are formed on the emitter layer, and a rear electrode formed on the semiconductor substrate.
The emitter layer is formed by doping a first surface of the semiconductor substrate with a dopant. In consideration of a contact resistance between the front electrode and the emitter layer, the doping may be performed with a high concentration of the dopant.
However, in order to minimize recombination occurring at a surface of the solar cell, the doping may be performed with a low concentration of the dopant. As such, when the emitter layer is formed with a uniform doping concentration, necessary characteristics of the solar cell cannot be entirely satisfied (or met).
A silicon solar cell has been provided in which a high concentration emitter portion is formed together with an emitter layer at a region where the front electrode is formed. In order to form the high concentration emitter portion, a dopant is additionally applied after an insulation layer is patterned through photolithography and etching processes. However, since the above may require expensive equipment and materials to pattern the insulation layer, as well as an additional application of the dopant, a manufacturing process of the silicon solar cell may be complex.